Merge pull request #517 from yui-knk/explanation_of_Digraph

More explanation for Digraph algorithm

lib/lrama/digraph.rb

@@ -2,10 +2,28 @@
 # frozen_string_literal: true
 
 module Lrama
-  # Algorithm Digraph of https://dl.acm.org/doi/pdf/10.1145/69622.357187 (P. 625)
+  # Digraph Algorithm of https://dl.acm.org/doi/pdf/10.1145/69622.357187 (P. 625)
   #
-  # @rbs generic X < Object -- Type of a member of `sets`
-  # @rbs generic Y < _Or    -- Type of sets assigned to a member of `sets`
+  # Digraph is an algorithm for graph data structure.
+  # The algorithm efficiently traverses SCC (Strongly Connected Component) of graph
+  # and merges nodes attributes within the same SCC.
+  #
+  # `compute_read_sets` and `compute_follow_sets` have the same structure.
+  # Graph of gotos and attributes of gotos are given then compute propagated attributes for each node.
+  # In the case of `compute_read_sets`:
+  #
+  # * Set of gotos is nodes of graph
+  # * `reads_relation` is edges of graph
+  # * `direct_read_sets` is nodes attributes
+  #
+  # In the case of `compute_follow_sets`:
+  # * Set of gotos is nodes of graph
+  # * `includes_relation` is edges of graph
+  # * `read_sets` is nodes attributes
+  #
+  #
+  # @rbs generic X < Object -- Type of a node
+  # @rbs generic Y < _Or    -- Type of attribute sets assigned to a node which should support merge operation (#| method)
   class Digraph
     # TODO: rbs-inline 0.10.0 doesn't support instance variables.
     #       Move these type declarations above instance variable definitions, once it's supported.

sig/generated/lrama/digraph.rbs

@@ -1,10 +1,28 @@
 # Generated from lib/lrama/digraph.rb with RBS::Inline
 
 module Lrama
-  # Algorithm Digraph of https://dl.acm.org/doi/pdf/10.1145/69622.357187 (P. 625)
+  # Digraph Algorithm of https://dl.acm.org/doi/pdf/10.1145/69622.357187 (P. 625)
   #
-  # @rbs generic X < Object -- Type of a member of `sets`
-  # @rbs generic Y < _Or    -- Type of sets assigned to a member of `sets`
+  # Digraph is an algorithm for graph data structure.
+  # The algorithm efficiently traverses SCC (Strongly Connected Component) of graph
+  # and merges nodes attributes within the same SCC.
+  #
+  # `compute_read_sets` and `compute_follow_sets` have the same structure.
+  # Graph of gotos and attributes of gotos are given then compute propagated attributes for each node.
+  # In the case of `compute_read_sets`:
+  #
+  # * Set of gotos is nodes of graph
+  # * `reads_relation` is edges of graph
+  # * `direct_read_sets` is nodes attributes
+  #
+  # In the case of `compute_follow_sets`:
+  # * Set of gotos is nodes of graph
+  # * `includes_relation` is edges of graph
+  # * `read_sets` is nodes attributes
+  #
+  #
+  # @rbs generic X < Object -- Type of a node
+  # @rbs generic Y < _Or    -- Type of attribute sets assigned to a node which should support merge operation (#| method)
   class Digraph[X < Object, Y < _Or]
     interface _Or
       def |: (self) -> self